The version.cc file will from now on be controlled on
bleeding edge and on trunk. The next version to use will
always be max(bleeding_edge_version, trunk_version) + 1.

The trunk and bleeding_edge versions are not semantically
tied together. The trunk branch can be used to make
independent point releases of bleeding_edge revisions.

The version on bleeding_edge will be increased if:
- the lkgr version is smaller than the version of the latest
  revision,
- the lkgr version is not a version change itself,
- the tree is not closed for maintenance.

This will allow chromium to refer directly to bleeding_edge
revisions of v8. The v8 versions will not be unique, but
they will change as often as possible, dependent on the lkgr
cycle time and the frequency this script is called.

BUG=391261
LOG=n
TEST=tools/push-to-trunk/script_test.py
TEST=tools/push-to-trunk/bump_up_version.py --dry_run
R=jarin@chromium.org

Review URL: https://codereview.chromium.org/389353003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22421 ce2b1a6d-e550-0410-aec6-3dcde31c8c00